Apparatus for crimping or corrugating sheet metal



y 9, 1961 J. J. ROBINSON 2,983,302

APPARATUS FOR CRIMPING OR CORRUGATING SHEET METAL Filed July 30, 1959 5 Sheets-Sheet 1 FIG. I

INVENTOR. JAMES J. ROBINSON ATTORNEY y 1961 J. J. ROBINSON 2,983,302

APPARATUS FOR CRIMPING 0R CORRUGATING SHEET METAL Filed July 30. 1959 5 Sheets-Sheet 2 FIG. 2

DIRECTION OF FEED OF STOCK INVENTOR. JAMES J ROBINSON ATTORNEY y 9, 1951 J. J. ROBINSON 2,983,302

APPARATUS FOR CRIMPING OR CORRUGATING SHEET METAL Filed July 30, 1959 5 Sheets-Sheet 3 FIG. 3

INVENTOR.

JAMES J. ROBINSON ATTORNEY May 9, 1961 J. J. ROBINSON APPARATUS FOR CRIMPING OR CORRUGATING SHEET METAL Filed July 50, 1959 5 Sheets-Sheet 4 FIG. 4

INVENTOR. JAMES J. ROBINSON ATTORNEY May 9, 1961 J. J. ROBINSON APPARATUS FOR CRIMPING OR CORRUGATING SHEET METAL Filed July 30, 1959 5 Sheets-Sheet 5 FIG. 6

DIRECTION OF FEED OF STOCK 2| DIRECTION OF FEED OF STOCK INVENTOR. JAMES J. ROBINSON BY E ATTORNEY United States Patent APPARATUS FOR CRINHING OR CORRUGATING SHEET METAL James J. Robinson, 4162 Kessler Blvd., North Drive,

Indianapolis, Ind.

Filed July 30, 1959, Ser. No. 830,578

19 Claims. (Cl. 153-76) This invention relates generally to metal forming or piercing apparatus, and in particular to a machine for continuously forming metal strips or sheets into sinuous or corrugated configurations of various shapes or sizes and suitably coined, lanced, punched, perforated or sheared.

Sheet metal folded upon itself to provide a generally sinuous configuration has many conventional applications. By suitably bonding face sheets to the margins of the folds, the resulting product may be utilized as an inner-fin heat exchanger member, through which heating and cooling fluids or gases may be circulated. The formed metal sheets may also be utilized in certain electronic devices, and when formed radially, can be used as expansion members, stiffener ribs for lightweight pressure vessels, etc. The formed metal sheets also can be used as covering or masking members wherever their surface provides the desired aesthetic effect. By bonding various materials, such as metal, wood, wood veneers, leather, plastic, fibre glass and the like as a face sheet to the formed metal, the resulting product may be utilized as structural panels in missile or aircraft structures or as conventional architectural structural panels which are characterized by rigidity and lightness in weight.

Conventionally, in the end products of the type referred to above, the required corrugations or folds are placed in the metal sheets by means of a series of rollers or formers which rotate in planes parallel to the axis of the folds and to the direction of movement of the stock through the rollers. The operation of the apparatus is such that the stock being formed or processed is accurately and continuously fed into the apparatus without the necessity for interior feeding devices. The machinery required for this type of forming is characteristically complicated and diflicult to adjust.

The apparatus of the present invention utilizes opposed dies which move transversely to the plane of the stock, one of the dies moving, additionally, in a direction parallel to the plane of the stock.

It is an object of the present invention, therefore, to provide an apparatus for forming corrugated or folded metal sheets in which the forming of the folds in the metal stock occurs without drawing or otherwise applying extensive tensile stress to the metal.

A further object of the present invention is to provide an apparatus of the type described having means for producing sequential motion of opposed forming dies whereby stock is self-fed into the apparatus and is formed or processed at a relatively rapid rate.

The full nature of the invention will be understood from the accompanying drawings and the following description and claims:

Fig. 1 is a side elevational view of apparatus embodying the present invention taken from the left side thereof.

Fig. 2 is a side elevational view of the apparatus taken from the right side thereof.

Fig. 3 is a front view of the upper portion of the apparatus.

Patented May 9, 1961 Fig. 4 is an enlarged detailed view of a portion of the apparatus.

Fig. 5 is an enlarged view of one cam forming a part of the apparatus.

Fig. 6 is an enlarged view of another cam forming a part of the apparatus.

Fig. 7 is a fragmentary view showing the dies in one position in their sequence of movement during operation of the apparatus.

Fig. 8 is a view similar to Fig. 7, but showing the dies in a further sequential position.

Fig. 9 is a view similar to Fig. 8, but showing the dies in a still further sequential position.

Fig. 10 is a view similar to Fig. 9, but showing the dies in a still further sequential position.

Fig. 11 is a fragmentary, perspective view of one form of product which may be manufactured by use of the apparatus of the present invention.

Referring initially to Figs. 1, 2 and 3, the apparatus includes a generally rectangular structure formed by side plates 10 and 10a which are spannned by a transverse base plate 11. The apparatus may be supported on a suitable bench structure 12 carrying driving means such as the electric motor 13. Extending transversely across the plates 10 and 19a is a shaft 14 which is journaled in suitable bearings (not shown) carried by the plates. At its outer end the shaft 14 is provided with a multiple, V-belt pulley 1 6 which receives rotary motion by means of the belt 17 from the motor 13.

The shaft, adjacent its outer ends, also has rotationally locked thereto two outer cams 18 and 18a. An inner cam 19, not visible in Fig. 1 but shown in detail in Fig. 6, is also rotationally locked to the shaft 14 and is disposed between the inner side of the cam 18 and the adjacent side plate 10. Similarly, an inner cam 19a (Fig. 2) is also rotationally locked to the shaft 14 and disposed between the inner side of the cam 18a and the side plate The periphery of the cam 18 is engaged by cam follower rollers 21 and 22 which are carried by rocker arms 23 and 24, respectively. The rocker arms are pivotally supported on stub shafts 26 and 27 and a tension spring 28 extends between the two adjacent ends of the rocker arms urging the rollers 21 and 22 against the periphery of cam 18. Spring 28 is carried by adjustable tension brackets 29 which permit adjustment of the force urging the ends of the rocker arms toward each other as will be noted from Fig. 2. The opposite side of the apparatus is further provided with rocker arms whose function, configuration and mounting are identical to those just described. In Fig. 2, elements having counterparts in Fig. 1 are provided with corresponding reference numerals but with the sufiix a. 7

Referring now principally to Figs. 1, 3 and 4, it may be seen that the rocker arm 23 is apertured to receive the end of a shaft 3 1 which has a rectangular central portion 31a, its rounded opposite end being received by an appropriate aperture in the rocker arm 23a. At spaced points along the portion 31a the shaft 31 has rigidly secured thereto brackets 32 which support rollers 33. The angle of inclination of the brackets 32 and hence the vertical distance of the rollers 33 from a horizontal plane containing the axis of the shaft 31 may be adjusted by varying the angular attitude of the shaft with relation to the rocker arms, this adjustment being fixed by means of the set-screws 34 which fix the shaft with relation to the rocker arms.

As may best be seen in Fig. 3, the rollers 33 bear against the underside of a die supporting member 36 which extends transversely across between the side plates 10 and 10a. The member 36 is free for vertical movement, but held against movement in other planes than the i V V vertical plane by means of stationary guide posts 37, the member 36 being free for vertical motion alone and the posts being rigid and depending from a die block 38. Compression springs 39 extend between the die block 38 and the member 36. Centrally upon the member 36 there is rigidly supported, by means of hand screws 41, a lower die 42 whose upper end has a longitudinally bifur-' cated configuration, as will be evident from Figs. 7-10. The lower die extends freely between the die 42, block 38 and a plate 43 rigidly attached thereto.

The die block or guide 38 is supported at its opposite ends by means of members 44 and 44a rigidly attached to theside plates and 10a. The horizontal position of the stationary die block 38 maybe adjusted by means of the screws 46. From the foregoing it will be evident that, as the rocker arms 23 and 23a are moved in a vertical plane about their pivots by. the cams 18 and 18a, the member 36, and consequently the lower die 42, will be reciprocated in a vertical plane, with the length of the gtoke depending upon the adjusted position of the rollers V The rocker arms 24 and 24a similarly carry a shaft 47 which has a rectangular central portion 48 upon which are mounted the rollers 49. Setscrews 51 permit fixing the angular position of the shaft 47 with relation to the rocker arms and hence the vertical distance of the rollers 49 from the horizontal plane containing the axis of the shaft 47. The rollers 49 bear against the upper side of a member 52 which extends transversely across the apparatus and is slidably received upon the die guide posts 53. The guide posts are rigidly carried by and extend upwardly from an upper die block 54. Compression springs 56 extend between the member 52 and the block 54. By means of hand screws 57, the member 52 has rigidly attached thereto an upper die 58 which, as may be seen in Figs. 7-10, has a longitudinally bifurcated configuration similar to the lower die 42. The upper die 58 extends freely between a die block 54 and a member 59 rigidly attached thereto. It may thus be seen that as the rocker arms'24 and 24a are pivotally moved by the cams 18 and 18a, the upper die 58 will be reciprocated in a vertical plane with the magnitude of the stroke depending upon the adjusted positions of the rollers 49.

The means for moving the upper die 58 and the member 54 in a horizontal plane upon rotation of the inner earns 19 and 19a will now be described. As will be evident from Fig. 1, the die block 54 extends into the central, rectangular apertures in the members 44 and 44a and is slidably received upon a horizontal guide post 61, the posts 61 being rigidly supported by the member. As may best be seen in Fig. 4, the opposed ends of the die block 54 have extending therefrom stub shafts 54a which are received within bushings 54b carried by elon' gated links 62 and 62a. The free end of the link 62 is pivotally attached, by means of pin 63, to a member 64. The opposite end of the member 64 is formed to provide a T-head 65 which fits within an arcuate T-slot 75. The slot 75 is formed by registering arcuate grooves and shoulders in an underlying lever 66 and an overlying plate 67 rigidly attached thereto by means of screws 7 0. The lever 66 is pivotally supported on 'a stub shaft 68 which extends outwardlyfrom the side plate 10.

The one of the levers carried by the side plate 19 carries a pin 69. Pivotally supported on the pin 69 is an extending end of a horizontally movable carriage 71. As may best be seen in Fig. 6, the carriage 71 is supported for free horizontal movement by means of rollers 72 which, in turn, are supported on the side plate 10. The carriage 71 supports spaced rollers or cam followers 73 which engage the periphery of the inner cam 19. It may thus be seen that horizontal displacement of the carriage 71 caused by rotation of the inner cam 19, serves to pivotally move the lever 66 about its pivot 68.

' This motion is transmitted through the member 64 and the link 62 to provide a horizontal, reciprocating stroke for the die block 54 and, consequently, the upper die 58. It will be further evident that the magnitude of this stroke may be adjusted by altering the position of the member 64 within the slot '75. For example, to increase the stroke, the plate 67 may be loosened upon the lever 66 and the member 64 positioned at the upward end of the slot 75. Subsequent tightening of the plate 67 against the lever 66 serves to hold the member 64 rigidly in its new position, thereby providing the line 62 with increased length of stroke. Because of the arcuate form of the slot, the member 64 is rigidly held therein without requiring the use of setscrews or clamps. It will be evident from Fig. 2. that the link, lever and carriage have identical counterparts adjacent the side plate 10a and these counterpart elements are given reference numerals with the sufiix a.

Referring now to Fig. 5, the contour of the outer cams 18 and 18a will now be described. While one. cam 18 and its associated rocker arms 23 and 24 are described in detail with reference to Fig. 5, it will be understood that cam 18a and its associated rocker arms 23a and 24a are identical in configuration to the parts shown in Fig. 5. The periphery of the cam 18 is defined by two connecting arcs of equal length, the two points of junction of the arcs being indicated at 76 and 77, the arc extend ing between points 76 and 77 on the left-hand side of the shaft 14 having a radius R and concentric with the shaft 14. The are joining the points 76 and 77 on the righthand side of the shaft also has a radius R, but the center of this are is displaced sidewardly along the bisecting radius of the first-mentioned arc. The center of this are is thus sidewardly displaced a distance indicated at 78. The portion of the cam to the right of the shaft 14, as viewed in Fig. 5, is thus the low side of the cam and the portion of the cam lying to the left of the shaft is the high side of the cam. Adjacent the bisecting radius of the are forming the high side of the cam, the periphery of the cam is relieved or flattened at 79, as indicated by the dimension 81. It will be understood that the dimensions 78 and 81 and the radius R are exaggerated herein so that the contour of the cam can be more easily visualized from the drawing. The letters A, B, C and D have been shown in Fig. 5 spaced about the center of the cam. A reference marking x has also been indicated on the cam 18 in Fig. 5. The locations A, B, C and D and the marking x on the cam 18 will be utilized to define the successive positions of the cam in subsequently explaining the operation of the apparatus.

Referring now to Fig. 6, the contour of the inner cam 19 will be described in detail and it should be kept in mind that cam 19 has an identical counterpart, cam 19a, which cooperates with a carriage 71a and followers 73a identical with the carriage 71 and followers 73, respectively, shown in Fig. 6. The periphery of theinner cam 19 is defined by two arcs, of equal length, both concentric with the shaft 14. One are making up the periphery of cam 19 has a radius which is greater, by the dimension indicated at 82, than the radius of the oppositearc. The two arcs are smoothly joined by the changeover surfaces 83 and 84. The portion of the cam to the right of the shaft 14 may thus be considered to be the low side of the cam and the portion to the left of the shaft 14 in Fig. 6 may be considered to be the high side of the cam. As may be seen from a comparison of Figs. 5 and 6, and the position of the cam key 86, the cams are aligned on the shaft so that the low side of each cam is on the same side of the shaft 14. The letters A, B C and D in Fig. 6 indicate the same cam positions as are indicated in Fig. 5. It should be noted that both cams 18 and 19 rotate clockwise as viewed in Figs. 5 and 6 and that the change-over portions 83 and 84 on the cam 19 are advanced slightly in the direction of rotation when cam 19 is in its position of Fig. 6. It should further be noted that the direction of feed of the metal stock to be processed is indicated by arrows in Figs. 5 and 6.

In Fig. 7 the stock is indicated at 87 as it moves toward the interfitting jaws of the upper and lower dies 42 and 58, the folded or processed stock being indicated at 87:: as it emerges from the dies. The means for supporting a roll of metal stock to be processed is not shown herein since it may take any suitable form and comprises no part of the present invention. The stock, while shown in Fig. 7, has been omitted from Figs. 8, 9 and 10 so that the sequence of movement of the dies will not be obscured.

Referring now to Figs. 5-10, a cycle of operation of the apparatus will now be described. With the cams 18 and 19, and their counterparts 18a and 19a in the respective portions shown in Figs. 5 and 6, the followers 21 and 22 will both be on high portions of the cam 18 so that the die 58 will be at the extremity of a downward or closing stroke and the die 42 will be at the extremity of an upward or closing stroke. The followers 73 will be positioned by cam 19 so that the carriage 71 and consequently the upper die 58 will be at the extremity of a leftward or backward stroke. Under these conditions the dies will be fully closed as indicated in Fig. 7 with upper die 58 in its leftward or backward position. In such position it should be noted that the ends of the dies are pressed tightly against the stock and against the adjacent anvil surfaces provided by the members 38 and 54.

As the reference point x on the cam 18 moves from position B to position C, that is, as shaft 14 rotates through 90 clockwise, the follower 21 will move inwardly toward the shaft 14, thereby causing the lower die 42 to be retracted, as indicated in Fig. 8, in a full downward or opening stroke. During this time the upper die 58 holds its extended or closed position, as shown in Fig. 8, however, as the relieved portion 79 on cam 18 passes beneath the follower 22, the upper die will be lifted slightly. As this slight lifting motion is imparted to the upper die, the change-over portions 83 and 84 will pass across their respective cam followers 73, causing the carriage 71 to shift rightwardly, or forwardly. This forward movement of the carriage 71 causes a rightward, or forward shifting of the die block 54 and the upper die 58. Motion of the upper die and die block is such as to shift these elements from their broken line positions of Fig. 8 into their solid line positions. Since this sideward motion of the upper die occurs simultaneously with the slight upward motion of the upper die caused by the relieved portion 79, the path of the end of the die 58 will be substantially as indicated by the broken line identified at 91 in Fig. 8. As the upper die 58 moves from its broken line position of Fig. 8 into its solid line position, it will be evident that the stock 87 (Fig. 7) will be advanced into the apparatus and positioned for the next fold-forming stroke of the dies. The slight upward movement of the die 58 as it is moved sidewardly, relieves the frictional forces which would otherwise be generated upon sideward movement of the upper die and allows the stock to move freely across the face of the die block 38.

As the reference location 2; on cam 18 is rotated from location C to location D, that is, as the shaft 14 rotates an additional 90, the lower die 42 makes a complete upward or closing stroke as the follower 21 moves from the low point to a high point on cam 18. The lower die is thus moved from its broken line position of Fig. 9 into its solid line position. The upper die 58 remains stationary in extended or in full closed position. The closing stroke of the lower die 42 thereby forms a fold in the metal stock which is held by the upper die.

As the reference location x on cam 18 moves from location 1) to location A, that is, as the shaft 14 rotates clockwise through an additional 90, the follower 22 moves from a high point to a low point on cam 18 and the upper die 58 makes a full upward or opening stroke.

The lower die 42 holds its upward position as shown in Fig. 10, however, as the relieved surface 79 on cam 18 passes across the follower 21, the lower die will be moved downwardly a slight amount as indicated by the broken lines identified at 92 in Fig. 10. As the lower die makes this slight downward movement, the change-over portions '83 and 84 on cam 19 will pass across their adjacent followers 73, causing the carriage 71 to move leftwardly or in a backward direction. The upper die 58 and the die block 54 are thus moved from their broken line position of Fig. 10 into their solid line position. It should be noted that sideward movement of the upper die 58 and die block 54 occurs with the die 58 in full upward or open position. The simultaneous slight downward movement of the lower die 42 relieves the pressure of the stock against the upper die and die block so that this sideward movement of the upper die and die block cam occur without generation of frictional forces. It should further be noted that in the sideward movement of the upper die illustrated in Fig. 10, the upper die passes over the stock, leaving it in position on the lower die.

As the location at is moved from location A to location B, to complete a cycle, the upper die 58 makes a full downward or closing stroke and the lower die retains its extended or closed position. The upper die remains in the horizontal position shown in Fig. 10. The upper and lower dies thus again attain their positions of Fig. 7 and a new fold is formed in the stock. Further rotation of shaft 14 and, consequently, of cams 18 and 19, repeats the cycle just described.

It should be noted that the movement of the upper die 58 in forward or rightward direction serves to advance the stock into the apparatus and a fold is formed with each full revolution of the shaft =14. The particular formation of the cams 18 and 19 and their relative positioning provides the required sequence of motion of the dies to produce folds in the stock and to advance the stockinto the apparatus. While the cams 18 and 19 (and their counterparts 18a and 19a) are herein described as mounted upon the same shaft, it will be evident that they might be mounted on separate shafts as long as their correct relative position is maintained. It should further be noted that the cams may be rotated a relatively high speed so that stock may be folded or processed at a relatively rapid rate by the apparatus.

While the working faces of the upper and lower dies are herein shown and described as longitudinally bifurcated, it will be evident that the dies might be shaped to provide other configurations and might take the form of metal piercing members so that stock might be perforated in a desired pattern by the apparatus.

As shown in Fig. 11, the folded sheets or strips formed in the apparatus of the present invention may have face sheets 191 and 102 suitably bonded to the margins of the fold. The resulting product is characterized by strength and rigidity, but is relatively light in Weight. The apparatus of the present invention may be particularly utilized in forming aluminum sheets or strips, but can also suitably form copper or stainless steel sheets or strips. The folds may be formed in the stock at an angle to the axis or center line of the strips of stock by feeding the stock into the dies at the required angle.

it should further be noted that the lower die guide or block 33 may be adjustably positioned in horizontal plane by the adjusting screws 46 and may be adjustably positioned in a vertical plane by means of suitable shims as indicated at 40 in Fig. 4. These adjustments permit the height of the folds made in the stock to be adjusted, as desired. The upper die guide or block 54 has no adjustment in the vertical plane, but the magnitude of its horizontal stroke may be adjusted by changing the position of the member 64 in the arcuate slot 64b, as previously described. The variations in the length of the stroke of each die in the vertical plane may be made by varying the angle of extension of the brackets carrying the rollers 33 and 49. The apparatus may thus be adjusted to accommodate stock of various thicknesses and to form folds of various dimensions Without changing the drive earns 18, 18a, 19 and 19a. The adjustment mechanism can also be operated so that fins or folds having differing heights can be formed as the stock progresses through the dies. Under some conditions, a stripper device (not shown) may be mounted between the upper and lower dies to assist in removing the formed section of the stock fromlthe dies. While dies of relatively small width have'been shown and described herein, it will be understood that much wider dies might also be used and a series of dies might be used to attain certain configurations. As previously pointed out the forming operation performed by the apparatus of the present invention is in the nature of a fold, rather than a deep draw of the stock, and, as a result, a minimum amount of internal stress and work hardening is created in the processed material.

While the invention has been disclosed and described in some detail in the drawings and foregoing description,

selves to persons skilled in this art and within the broad scope of the invention, reference being had to the appended claims.

The invention claimed is:

1. An apparatus for continuously forming parallel folds in a strip of metal stock fed into the apparatus, said apparatus including opposed die blocks disposed on opposite sides of the stock, a first die extensible from one of said die blocks in a closing stroke and retractable into said one die block in an opening stroke, a second die extensible from the other of said die blocks in a closing stroke and retractable into said other die block in an opening stroke, the direction of the closing and opening strokes of said dies being parallel and normal to the plane of the stock, each of said die blocks providing an anvil surface cooperating with its opposed die when in extended position, mounting means supporting said one die block and said first die for movement in a direction normal'to the direction of the opening and closing strokes of said dies, and means for sequentially moving said dies and said one die block comp-rising a first rotatable cam, a first rocker arm carrying a cam follower engaging the periphery of said first cam and having an operative connection with said first die whereby when its cam follower is at a maximum distance from the center of said first cam said first die is at the extreme of a closing stroke, a second rocker arm carrying a cam follower engaging the periphery of said first cam at a point thereon diametrically opposed to the point of engagement of said first rocker arm cam follower and having an operative connection with said second die whereby when its cam follower is at a maximum distance from the center of said first cam said second die is at the extreme of a closing stroke, the periphery of said first cam being defined by twd connecting arcs of equal length, one are having a radius R and concentric with the axis of rotation of said first cam, the other arc having a radius R but concentric with a point displaced along the bisecting radius of said one arc, the periphery of said first cam having a relieved surface at the outer end of said bisecting radius, asecond rotatable cam, a thrust member carrying spaced cam followers adapted to engage the periphery of said second cam at diametrically spaced points, said thrust member having an operative connection with said one die block and said first die for moving said last mentioned die and die block between a forward and backward position in a direction normal to the direction of the closing and opening strokes of said dies, the periphery of said second cam being defined by two arcs of equal length concentric with the axis of rotation of said second cam with one arc having a greater radius than the other, said cams being rotated by a single driving shaft and oriented with relation to each other so that their low sides are generally aligned, whereby as said cams are rotated said dies are sequentially moved from a reference position in which both dies are at the extremity of a closing stroke and said first die is in its said backward position as follows: (1) said second die moves through an opening stroke and said first die moves into its said forward position, (2) said second die completes a closing stroke, (3) said first die completes an opening stroke and moves into its said backward position as said second die .holds its closed position, (4) said first die completes a closing stroke as said second die retains its position at the extremity of said closing stroke to again attain'the said reference position and complete a cycle, said relieved surface on said first cam causing said first die to move through a portion of an opening stroke as it moves toward its said forward positiomsaid relieved surface furher causing said second die to move through a portion of an opening stroke as said first die moves toward its said backward position, whereby a complete fold is formed in said stock with each full revolution of said cams.

2. An apparatus as claimed in claim 1 in which the said operative connection between said thrust member and said first die includes a linkage assembly comprising an elongated element pivotally supported at one of its ends and carrying an arcuately formed T-slot at its opposite end, said thrust member being pivotally comiected to an intermediate portion of said element, and a link having one end adjustably positioned along said slot and its other end operatively connected to said first die, whereby the adjusted position of said link end in said slot determines the distance of travel of said first die in attaining its said forward and backward positions.

3. An apparatus as claimed in claim 1 in which said operative connection between said thrust member and said first die is adjustable to vary the distance of travel of said first die in attaining its said forward and backward positions.

4. An apparatus as claimed in claim 1 in which said operative connections between said first and second rocker arms and said first and second dies are adjustable to vary the closing and opening strokes of said dies.

5. An apparatus for continuously forming parallel folds in a strip of metal stock fed into the apparatus, said apparatus including a first die extensible toward the stock in a closing stroke and retractable away from the stock in an opening stroke, a second die disposed adjacent the opposite side of the stock extensible toward the stock in a closing stroke and retractable therefrom in an opening stroke, the direction of the closing and opening strokes of said dies being parallel and normal to the plane of the stock, mounting means supporting said' first die for movement in a direction normal to the direction of the opening and closing strokes of said dies, and means for sequentially moving said dies comprising a first rotatable cam, a first rocker arm carrying a cam follower engaging the periphery of said first cam and having an operative connection with said first die whereby when its cam follower is at a maximum distance from the center of said first cam said first die is at the extreme of a closing stroke, a second rocker arm carrying a cam follower engaging the periphery of said first cam at a point thereon diametrically opposed to the point of engagement of said first rocker arm cam follower and having an operative connection with said second die whereby when its cam follower is at a maximum distance from the center of said first cam said second die is at the extreme of a closing stroke, the periphery of said first cam being defined by two connecting arcs of equal length, one are having a radius R and concentric with the axis of rotation of said first cam, the other are having a radius R but concentric with a point displaced along the bisecting radius of said one arc, a second rotatable cam, a thrust member carrying spaced cam followers adapted to engage the periphery-of said second cam at diametrically spaced points, said thrust member having an operative connection with said first die for moving said last mentioned die between a forward and backward position in a direction normal to the direction of the closing and opening strokes of said dies, the periphery of said second cam being defined by two arcs of equal length concentric with the axis of rotation of said second cam with one are having a greater radius than the other, said cams being rotated by a single driving shaft and oriented with relation to each other so that their low sides are generally aligned, whereby as said cams are rotated said dies are sequentially moved from a reference position in which both dies are at the extremity of a closing stroke and said first die is in its said backward position as follows: (1) said second die moves through an opening stroke and said first die moves into its said forward position, (2) said second die completes a closing stroke, (3) said first die completes an opening stroke and moves into its said backward position as said second die holds its closed position, (4) said first die completes a closing stroke as said second die retains its position at the extremity of a closing stroke to again attain the said reference position and complete a cycle, whereby a complete fold is formed in said stock with each full revolution of said cams.

6. An apparatus as claimed in claim 5, in which the said operative connection between said thrust member and said first die includes a linkage assembly comprising an elongated element pivotally supported at one of its ends and carrying an arcuately formed T-slot at its opposite end, said thrust member being pivotally connected to an intermediate portion of said element, and a link having one end adjustably positioned along said slot and its other end operatively connected to said first die, whereby the adjusted position of said link end in said slot determines the distance of travel of said first die in attaining its said forward and backward positions.

7. An apparatus as claimed in claim 5, in which said operative connection between said thrust member and said first die is adjustable to vary the distance of travel of said first die in attaining its said forward and backward positions.

8. An apparatus as claimed in claim 5, in which said operative connections between said first and second rocker arms and said first and second dies are adjustable to vary the closing and opening strokes of said dies.

9. An apparatus for continuously forming parallel folds in a strip of metal stock fed into the apparatus, said apparatus including opposed die blocks disposed on opposite sides of the stock, a first die extensible from one of said die blocks in a closing stroke, a second die extensible from the other of said die blocks in a closing stroke and retractable into said other die block in an opening stroke, the direction of the closing and opening strokes of said dies being parallel and normal to the plane of the stock, each of said die blocks providing an anvil surface cooperating with its opposed die when in extended position, mounting means supporting said one die block and said first die for movement in a direction normal to the direction of the opening and closing strokes of said dies, and means for sequentially moving said dies and said one die block comprising a first rotatable cam, a first rocker arm carrying a cam follower engaging the periphery of said first cam and having an operative connection with said first die whereby when its cam follower is at a maximum distance from the center of said first cam said first die is at the extreme of a closing stroke, a second rocker arm carrying a cam follower engaging the periphery of said first cam at a point thereon diametrically opposed to the point of engagement of said first rocker arm cam follower and having an operative connection with said second die whereby when its cam follower is at a maximum distance from the center of said first cam said second die is at the extreme of a closing stroke, the periphery of said first cam being defined by two connecting arcs of equal length, one are having a radius R and concentric with the axis of rotation of said first earn, the other are having a radius R but concentric with a point displaced along the bisecting radius of said one arc, the periphery of said first cam having a relieved surface at the outer end of said bisecting radius, a second rotatable cam, a thrust member carrying spaced cam followers adapted to engage the periphery of said second cam at diametrically spaced points, said thrust member having an operative connection with said one die block and said first die for moving said last mentioned die and die block between a forward and backward position in a direction normal to the direction of the closing and opening strokes of said dies, the periphery of said second cam being defined by two arcs of equal length concentric with the axis of rotation of said second cam with one are having a greater radius than the other, and means for rotating said cams in UIIiSOH, whereby as said cams are rotated said dies are sequentially moved from a reference position in which both dies are at the extemity of a closing stroke and said first die is in its said backward position as follows: (1) said second die moves through an opening stroke and said first die moves into its said forward position, (2) said second die completes a closing stroke, (3) said first die completes an opening stroke and moves into its said backward position as said second die holds its closed position, (4) said first die completes a closing stroke as said second die retains its position at the extremity of a closing stroke to again attain the said reference position and complete a cycle, said relieved surface on said first cam causing said first die to move through -a portion of an opening stroke as it moves toward its said forward position, said relieved portion further causing said second die to move through a portion of an opening stroke, as said first die moves toward its said backward position, whereby a complete fold is formed in said stock with each full revolution of said cams.

10. An apparatus as claimed in claim 9, in which the said operative connection between said thrust member and said first die includes a linkage assembly comprising an elongated element pivotally supported at one of its ends and carrying an arcuately for-med T-slot at its upposite end, said thrust member being pivotally connected to an intermediate portion of said element, and a link having one end adjustably positioned along said slot and its other end operatively connected to said first die, whereby the adjusted position of said link end in said slot determines the distance of travel of said first die in attaining its said forward and backward positions.

11. An apparatus as claimed in claim 9 in which said operative connection between said thrust member and said first die is adjustable to vary the distance of travel of said first die in attaining its said forward and backward positions.

12. An apparatus as claimed in claim 9 in which said operative connections between said first and second rocker arms and said first and second dies are adjustable to vary the closing and opening strokes of said dies.

13. An apparatus for continuously forming parallel folds in a strip of metal stock fed into the apparatus, said apparatus including a first die extensible toward the stock in a closing stroke and retractable away from the stock in an opening stroke, a second die disposed adjacent the opposite side of the stock extensible toward the stock in a closing stroke and retractable therefrom in an opening stroke, the direction of the closing and opening strokes of said dies being parallel and normal to the plane of the stock, mounting means supporting said first die for movement in a direction normal to the direction of the opening and closing strokes of said dies, and means for sequentially moving said dies comprising a first rotatable cam, a first rocker arm carrying a cam follower engaging the periphery of said first cam and having an operative connection with said first die whereby when its cam follower is at a maximum distance from the center of said first cam said first die is at the extreme of a closing stroke, a second rocker arm carrying a cam follower engaging the periphery of said first cam at a point thereon diametrically opposed to the point of engagement of said first rocker arm cam follower and having an operative connection with said second die whereby when its cam follower is at a maximum distance from the center of said first cam said second die is at the extreme of a closing stroke, the periphery of said first cam being defined by two connecting arcs of equal length, one are having a radius R and concentric with the axis of rotation of said first cam, the other arc having a radius R but concentric with a point displaced along the bisecting radius of said one arc, a second rotatable cam, a thrust member carrying spaced cam followers adapted to engage the periphery of said second cam at diametrically spaced points, said thrust member having an operative connection with said first die for moving said last mentioned die between a forward and backward position in a direction normal to the direction of the closing and opening strokes of said dies, the periphery of said second cam being defined by two arcs of equal length concentric with the axis of rotation of said second cam with one are having a greater radius than the other, and means for rotating said cams in unison, whereby as said cams are rotated said dies are sequentially moved from a reference position in which both dies are at the extremity ow a closing stroke and said first die is in its said backward position as follows: (1) said second die moves through an opening stroke and said first die moves into its said forward position, (2) said second die completes a closing stroke, (3) said first die completes an opening stroke and moves into its said backward position as said second die holds its closed position, (4) said first die completes a closing stroke as said second die retains its position at the extremity of a closing stroke to again attain the said reference position and complete a cycle, whereby a complete fold is formed in said stock with each full revolution of said cams.

14. An apparatus as claimed in claim 13, in which i the said operative connection between said thrust memher and said first die includes a linkage assembly comprising an elongated element pivotally supported at one of its ends and carrying an arcuately formed T-slot at its opposite end, said thrust member being pivotally connected to an intermediate portion of said element, and a link having one end adjustably positioned along said slot and its other end operatively connected to said first die, whereby the adjusted position of said link end in said slot determines the distance of travel of said first die in attaining its said forward and backward positions.

15. An apparatus as claimed in claim 13, in which said operative connection between said thrust member and said first die is adjustable to vary the distance of travel of said first die in attaining its said forward and backward positions.

16. An apparatus as claimed in claim 13, in which said operative connections between said first and second rocker arms and said first and second dies are adjustable to vary the closing and opening strokes of said dies.

17. An apparatus for continuously processing a strip of metal stock fed into the apparatus, said apparatus including a first die extensible toward the stock in a closing stroke and retractable away from the stock in an opening stroke, a second die disposed adjacent the opposite side of the stock extensible toward the stock in a closing stroke and rotatable therefrom in an opening stroke, the direction of the closing and opening strokes of said diesbeing parallel and normal to the plane of the stock, mounting means supporting said first die for movement in a direction normal to the direction of the opening and closing strokes of said dies, and means for sequentially moving said dies comprising a first rotatable earn, a first rocker armcarrying a cam follower engaging the periphery of said first cam and havingan opera tive connection with said first die whereby when its cam follower is at a maximum distance from the center of said first cam said first die is at the extreme of a closing stroke, a second rocker arm carrying a cam follower engaging the periphery of said first cam at a point thereon diametrically opposed to the point of engagement of said first rocker arm cam follower and having an operative connection with said second die whereby when its cam follower is at a maximum distance from the center of said first cam said second die is at the extreme of a closing stroke, the periphery of said first cam being defined by two connecting arcs of equal length, one are having a radius R and concentric with the axis of rotation of said first cam, the other are having a radius R but concentric with a point displaced along the bisecting radius of said one are, a second rotatable cam, a thrust member including a spaced cam follower adapted to engage the periphery of said second cam, said thrust member having an operative connection with said first die for moving said last mentioned die between a forward and backward position in a direction normal to the direction of the closing and opening strokes of said dies, the periphery of said second cam being defined by two arcs of equal length concentric with the axis of rotation of said second cam with one are having a greater radius than the other, and means for rotating said cams in unison, whereby as said cams are rotated said dies are sequentially moved from a reference position in which both dies are at the extremity of a closing stroke and said first die is in its said backward position as follows: (1) said second die moves through an opening stroke and said first die moves into its said forward position, (2) said second die completes a closing stroke, (3) said first die completes an opening stroke and moves into its said backward position as said second die holds its closed position, (4) said first die completes a closing stroke as said second die retains its position at the extremity of a closing stroke to again attain the said reference position and complete a cycle, whereby a processing opera tion is performed on said stock with each full revolution of said cams.

13. An apparatus for continuously processing a strip of metal stock fed into the apparatus, said apparatus including a first die extensible toward the stock in a closing stroke and retractable away from the stock in an opening stroke, a second die disposed adjacent the opposite side of the stock extensible toward the stock in a closing stroke and retractable therefrom in an opening stroke, the direction of the closing and opening strokes of said dies being parallel and normal to the plane of the stock, mounting means supporting said first die for movement in a direction normal to the direction of the opening and closing strokes of said dies, means for moving said dies through their opening and closing strokes comprising a rotatable earn, a first rocker arm carrying a cam follower engaging the periphery of said cam and having an operative connection with said first die whereby when its cam follower is at a maximum distance from the center of said carn said first die is at the extreme of a closing stroke, a second rocker arm carrying a cam follower engaging the periphery of said cam at a point thereon diametrically opposed to the point of engagement of said first rocker arm follower and having an operative connection with said second die whereby when its cam follower is at a maximum distance from the center of said cam said second die is at the extreme of a closing stroke, the periphery-of said cam being defined by two connecting arcs of equal length, one are having a radius R and concentric with the axis of rotation of said first cam, the other are having a radius R but concentric with a point displaced along the bisecting radius of said one arc, and means for intermittently moving said first die between a forward and backward position in a direction generally normal to the direction of the closing and opening strokes of said dies, whereby said dies are sequentially moved from a reference position in which both dies are at the extremity of a closing stroke and said first die is in its said backward position as follows: (1) said second die moves through an opening stroke and said first die moves into its said forward position, (2) said second die completes a closing stroke, (3) said first die completes an opening stroke and moves into its said backward position as said second die holds its closed position, (4) said first die completes a closing stroke as said second die retains its position at the extremity of a closing stroke to again attain the said reference position and complete a cycle whereby a processing operation is performed on said stock with each full revolution of said cam.

19. An apparatus for continuously forming parallel folds in a strip of metal stock fed into the apparatus, said apparatus including a first die extensible toward the stock in a closing stroke and retractable away from the stock in an opening stroke, a second die disposed adjacent the opposite side of the stock extensible toward the stock in a closing stroke and retractable therefrom in an opening stroke, the direction of the closing and opening strokes of said dies being parallel and normal to the plane of the stock, mounting means supporting said first die for movement in a direction normal to the direction of the opening and closing strokes of said dies, and means for sequentially moving said dies comprising a first rotatable cam, a first cam follower engaging the periphery of said first cam and having an operative connection with said first die whereby when said first cam follower is at a maximum distance from the center of said first cam said first die is at the extreme of a closing stroke, a second cam follower engaging the periphery of said first cam at a point thereon diametrically opposed to the point of engagement of said first cam follower and having an operative connection with said second die whereby when said second cam follower is at a maximum distance from the center of said first cam said second die is at the extreme of a closing stroke, the periphery of said first cam being defined by two connecting arcs of equal length, one are having a radius R and concentrio with the axis of rotation of said first cam, the other are having a radius R but concentric with a point displaced along the bisecting radius of said one arc, a second rotatable cam, cam follower means adapted to engage the periphery of said second cam at diametrically spaced points and having an operative connection with said first die for moving said last mentioned die between a forward and backward position in a direction normal to the direction of the closing and opening strokes of said dies, the periphery of said second cam being defined by two arcs of equal length concentric with the axis of rotation of said second cam with one are having a greater radius than the other, said cams being rotated by a single driving shaft and oriented with relation to each other so that their low sides are generally aligned, whereby as said cams are rotated said dies are sequentially moved from a reference position in which both dies are at the extremity of a closing stroke and said first die is in its said backward position as follows: 1) said second die moves through an opening stroke and said first die moves into its said forward position, (2) said second die completes a closing stroke, (3) said first die completes an opening stroke and moves into its said backward position as said second die holds its closed position, (4) said first die completes a closing stroke as said second die retains its position at the extremity of a closing stroke to again attain the said reference position and complete a cycle, whereby a complete fold is formed in said stock with each full revolution of said cams.

References Cited in the file of this patent UNITED STATES PATENTS 2,085,570 Blount June 29, 1937 2,101,906 Hopkinson Dec. 14, 1937 2,489,125 Dyson Nov. 22, 1949 2,697,970 Tipper Dec. 28, 1954 FOREIGN PATENTS 17,219 Great Britain Aug. 6, 1904 395,448 France Dec. 28, 1908 584,575 Great Britain Jan. 17, 1947 

